Fluid displacement device of the gear type



Dec. 2, 1947. c. A. MANN 2,431,817

Y FLUID DISPLACEMENT DEVICE OF THE GEAR TYPE Filed April 22, 1944 2 Sheets-Sheet 1 ma 24 a; #4 U0 mvmy'ron V Can. A. MANN BY W Dec. 2, 1947.

.C. A. MANN FLUID DISPLACEMENT DE VICE OF THE GEAR TYPE 2 Sheets-Sheet 2 Filed April 22, 1944 INVENTOR. 6204 A. HAHN Patented Dec. 2, 194'? D STATES:

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can a. Mann, payroll, Ghio; assignor' to." n; Christa Smith, Cincinnati, Ohio.

Ap'piicatien" April 22',

This invention: relates to fluid displacements devices of the gear type: and more particularly to" fluid: operated motors: and pumps:

One: object; of; the; invention is? to provide: such at fluid; displacement; device which has substantially perfect: hydraulic: balance; and to provide such' balance: without resorting to' mechanism or: conduits providedi solely for. the purpose of' balance:

K further objectv of: the inventionl is to provide: such a fluid: displacement device having an effi' ciency'greatly inzexcessmf the efficiency of: ordi nary gear displacementzdevices;v

further: objeciaof; the invention is to. provide such a device which both balance. and in-- creased emciencyare secured by a combinationofxintermeshing gears;

further. objedlfiofrthe invention is to provide such a device in" which each individual gear is subjected: to: substantially balanced peripheral pressure:v

Aiurthen objectzof'th'einvention is to provide aahydraulicallybalanced and highly efficient fluid operated motor: hav-ing differential power out-- puts.

Other objects or the invention: may appear as the device is described in detail.

In. the; accompanying drawings Fig; I is: a: longitudinal section: of: one form of the device showing the internal'mechanism partly in eleva tion andpartly. in -section: Fig. 2' is an enlarged sectional detail; of; apart? of Fig. 1'; Fig. 3- is a. front. elevation=of the device of Fig. 1; Fig.4 is an' -endtview offthe main shaft and spider of the: device of Fig: 1: Fig; diiseacside elevation of said shaft andspiden;Eigslfi isa: s'ectionalview of thetubularena of the shafti and spider; Rig. 7 isan elevation; partly in section; of: one part of the outerwall'oflthewo'rkzchamber; andFig. 8is an; end: elevation of saidipartof'the wall- 0f? the Work chamber.

In these drawingsi I: have illustrated one emb'odiment of the invention; which is designed:

primarily asa motor but: which, with or without minorr alterations; may be operated as'ia pump. It is to. be. understood; however; that devices em bodying the invention may take variousforms,

and that the word motor is herein'usedasa descriptive term and not: asra' limitation;

Preferably the invention comprises a com-- bination ofinterlocking gears; of any suitable" typeort types, mounted in" a: casing; and% so arranged with relation: one to: the other and: to; the: fluid passages that each: gear will be sub jected to substantially balanced peripheral presa 1944; Serial'No. 53%,3519" surei'. In the? illustrated embodiment the com? bination ofi gears. includes twoopposed gears:v mountedlon alcommon axis; and at least one of which isirotatable about; said. axis and constitutes; a-upowera transmission: element adapted to be com-- nected with exterior devices to: be; operated or: with am exterior source of; power: Mounted be twe'em saidopposed gears: are-intermediate gears: whichl mesh with the: respective opposed gears andxareso arrangedwithrelation'tolfluid passages. that. the fiuidjzwill be; inoperative contact with; the'teeth of: cache of saidintermediatev gears at. a: plurality oi: points; so spaced about the samethat the'gear will: be: subjected to substantially balanced peripheral'pressure: The device is operative: with: a. single group ofintermediategears meshing one withlthei otherand with the respec-- tive opposed; gears, but? in order. that the op posed; gears as well: as. the intermediate gears, maysbeisubjected to properly-balanced peripherall pressures: there; is; provided a plurality of groups;- of; intermediate. gears: which have: geared con-r nections with each of theopposed gears at points! spaced; substantially equal distances one from: the other about-the toothedrperipheries. of said opposedgears. 7

Supported" within the casing which encloses-J the combination: of gears are elements so arranged with relation to the respective inter- 30': mediate gears as. to form about the periphery of eachvofithelat-ter a plurality of passages or channels through which-thefluid flows in operative: engagement with the teeththereoi. Thus when the device operates-as a-motor the-fluid under pressure actsroneach intermediate gear at points so. spaced about the'latter that it is subjected to a-substantially balancedperipheral pressure, and the several intermediateg-ears transmit pressureto'theopposedgears atpointslso spaced about thelatterthat each of the opposed gearsis sub jectedtto substantiallybalanced peripheral pres--- sure, thereby maintaining; the motor as a whole inv substantially perfect hydraulic balance atv all speeds: of; operation; When the device is oper-' ated* as: a. pumpthei-power. applied to that: oneof the opposed gearsvwhich functions as a power transmission elementtis: transmitted to the intermediate-gearsati pointsspaced about said power transmittinggear as aforesaid, and each intermediate gear acts onthafluid at points spaced: about: said intermediatege'ar; and: the other of" saidzoppos'edgears meshes at peripherally spaced points with the; respective: intermediate gears;v thereby; maintaining the: motori in: substantially 56' perfect hydraulicbalanceati all speeds of: open- 3 ation. The illustrated embodiment of the invent'ion will be described as a motor with the understanding that it is not limited to such use.

In the drawings the device is shown as a differential motor which utilizes bevel gears in a spherical work chamber. As there shown, the mechanism is mounted in a substantially cylindrical casing I 03 one end of which is closed by an annular structure including an internal collar I04, a bearing 25 and oil seals I06. Mounted in the bearing I05 is a tubular element or shaft I01 and mounted in the tubular shaft I! for rotation with relation thereto is an inner or main shaft I08 which extends through the casing and is rotatably mounted at its other end in a bearing I09. The shaft I08 is provided within the casing with an enlarged portion IIO, preferably formed integral therewith, of substantially spherical contour which forms the inner wall of a work chamber, the outer wall of which is formed by an annular structure I I I having an inner surface conforming to a section of a sphere described about the same center as the spherical surface of the enlarged portion of the shaft and spaced therefrom. For convenience of manufacture this annular structure III is formed in two parts which are rotatably supported in the casing in running contact with the inner end of the collar i 04 and opposed end wall of the casing. Mounted within the spherical work chamber are two bevel gears II2 and H3 arranged in opposed relation one to the other, the gear II2 being connected with and in the present instance formed integral with the tubular shaft I01, and the gear II3 being rigidly secured to the casing in a position concentric with the axis of the shaft I08, the bearing I09 for that shaft being carried by this fixed gear. The enlarged or spherical portion I I0 of the shaft I03 is provided between the opposed gears with a plurality of projections or elongate lugs II a the outer surfaces of which conform'to or are in sealed contact with the inner surface of the annular structure III, the ends of adjacent lugs being spaced apart circumferentially to provide spaces in which intermediate gears may be mounted. In this instance a plurality of groups of intermediate gears are employed, the several groups being spaced apart substantially equal distances circumferentially of the shaft I08. Each group includes two bevel gears I I5 rotatably mounted in the work chamber, meshing one with the other and meshing respectively with the fixed gear H3 and the rotatable gear II2. Each of the intermediate gears is rotatably supported on a pintle H0 having one end mounted in the annular member III. The annular member III is connected with the shaft I08 so that the shaft, annular member and pinions rotate in unison about the axis of the shaft. The connection may be effected in any suitable manner, as by screws 2 I I extending through the respective parts of the annular member into the lugs I I4.

Channels are formed on a plurality of sides of each of the intermediate gears H5 and inlet and outlet ports are arranged to cause fluid to flow through these channels. That end portion of the shaft I08 having the enlargement is provided with a longitudinal bore extending through the enlargement. Mounted in this bore is a tube II I which is carried by and preferably formed integral with an annular end member IIO which is rigidly secured to the casing and provided with internal screw threads II9 to enable the same to be connected with a fluid conduit. The spherical enlargement of the shaft is provided about the tube II! with a circumferential passage I20 with which the tube is connected by means of a plurality of openings I2I. The inlet passage I20 is connected by suitable ports with the channels on the opposite sides of each of the intermediate gears. The gears being in the present instance arranged in pairs three inlet ports are provided for each pair of gears, see Figs. 5 and 6. The port I22 leads to a point between the gears at which the two gears move out of engagement one with the other and thus supplies fluid to the corresponding channels of both gears. Other ports I23 communicate with the channels on the opposite side of the gears adjacent the points at which the intermediate gears move out of engagement with the opposed gears II 2 and H3, so that the fluid flows in the same circumferential direction through the channels for each gear and in different circumferential directions through the channels of the two gears. A similar arrangement of ports in the annular structure III connects the outlet ends of the respective channels with an outlet passage I2 3 formed between the annular structure and the Wall of the casing. One part of the annular structure III, the left hand part in Fig. 1, is shown in Figs. 7 and 8. This part of the structure is provided with an inlet port I32 for each pair of intermediate gears and each such port leads to the outlet passage from the point at which the corresponding left hand intermediate gear I I5 moves in to mesh with the end gear II 3, that is, at the discharge end of the channel at one side of the intermediate gear. This part of the structure is also provided with an outlet port I33 for each pair of intermediate gears, each such port leading to the outlet passage from the point at which the two intermediate gears move in to mesh one with the other, that is, from the inner ends of the channels which communicate with the inlet ports I 23. The right hand part of the annular structure has outlet ports for the right hand intermediate gears in substantially the same arrangement as the .ports I 32 but in slightly different locations due to the difference in the number of teeth in the two end gears.

The opposed gears II2 and H3 are provided with different numbers of teeth, the rotatable gear II2 having, in the present instance, more teeth than the fixed gear H3. The gears of each pair of intermediate gears rotate in opposite directions and that intermediate gear which is in mesh with the fixed gear II3 will travel along that fixed gear, thereby causing the intermediate gears, the shaft I08 and the annular member III to rotate in the direction of said travel. The other gear of that pair of intermediate gears travels along the gear I I2 and, due to the greater number of teeth in gear II2, causes the latter and its shaft I01 to rotate in the same direction as the shaft I00 and at a different speed, the relative speeds being determined by the difference in the number of teeth in the gears II2 and H3. By providing the-gear II2 with less teeth than the gear II 3 it may be caused to rotate in the direction opposite the direction of rotation of the shaft I08.

The action of the fluid on the gears tends to exert an end thrust on the gear II2 and means are provided to hydraulically oppose this thrust and maintain hydraulic balance. For this purpose a hydraulic balancing chamber I25 is formed between the gear II2, the annular member III and the inner end of the collar I04 and is connected with the high pressure side of the motor assa e:

so that fluid under pressure is introduced into the balancing chamber I25to counterbalance the end thrust on the gear IIZ. The fluidmay enter the work chamber through either the passage I or the passage I24 and therefore both passages are connected with the balancing chamber and means are provided for preventing the flow of fluid through the balancing chamber to the low pressure passage. In the arrangement here shown (Fig. 2) the passage I2!) is connectedby a port I26 in the member III] with an annular channel I2! in the inner face of the gear H2, and a port I28 in the gear connects the channel with the chamber I225. The flow of fluid throughthe port I26 is controlled by a check valve I29 which opens toward the chamber I25. The passage I24 is connected with the chamber I by a port I30 in the annular member III and the flow of fluid through this port is controlled by a check valve I3I which opens toward the chamber I25. With i the check valves in the positions shown the chamber I25 is connected with the passage I24 and is disconnected from the passage I28. Thus when the motor is in operation the balancing chamber is in open connection with the high pressure side only of the motor and the pressure of the fluid in the chamber substantially counterbalances the end thrust on the gear IIZ.

While I have shown and described certain embodiments of my invention I wish it to be understood that I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a fluid displacement device of the gear type, a casing, a shaft rotatably supported in said casing, two gears mounted in said casing concentric with the axis of said shaft, one of said gears being rotatable and the other of said gears being held against rotation, a second shaft connected with the rotatable gear, a plurality of planetary gears connected with the first mentioned shaft for rotation therewith and having geared connection with the first mentioned gears, and means for causing fluid to flow in operative engagement with separated groups of teeth on each of said planetary gears.

2. In a fluid displacement device of the gear type, a casing, a shaft rotatably mounted in said casing, a bevel gear mounted in said casing about the axis of said shaft and held against rotation, at second bevel gear mounted in said casing for rotation about the axis of said shaft and with relation to said shaft, a second shaft connected with said rotatable gear, a plurality of pairs of planetary gears connected with the first mentioned shaft for rotation therewith and spaced about the same, the gears of each pair meshing one with the other and with the respective bevel gears, and means for causing fluid to flow in operative contact with separated groups of teeth on each planetary gear and in directions to cause the gears of each pair to rotate in opposite directions about their respective axes.

3. In a fluid displacement device of the gear type, a casing, a haft rotatably supported in said casing, a structure mounted in said casing about and in spaced relation to said shaft and connected with said shaft for rotation therewith, a bevel gear supported in said casing for rotation about the axis of said shaft, a second bevel gear mounted in said casing about the axis of said shaft and held against rotation, a plurality of planetary gears supported between said shaft and said structure for rotation therewith and having geared connection with the first mentioned gears, a shaft connected with the rotatable first mentioned gear, and means for causing fluid'to flow inoperative contact with separated groups of teeth ofeach of said planetary gears.

4.111 a fluid displacement device of the gear type, casing, a shaft rotatablysupported in said casing, a structuremounted in said casing about and in spaced relation to said shaft for rotation about the axis of said shaft,'a plurality of groups of pintles extending through the space between said shaft and said structure, said groups of pintles being spaced one from'the other about said shaft,;bev.el gears supported in the space between saids'haft andsaidstructureand spaced one from the other, one of said gearsbeing'rotatable and the other ofsaid gears being held against rotation, a shaft connected with said rotatable gear, a plurality of groups of gears rotatably mounted on the respective pintles, the gears of each group having geared connection one with the other and with the first mentioned gears, and means for causing fluid to flow in operative contact with separated sections of the toothed edge of each of the last mentioned gears.

5. In a fluid displacement device of the gear type, a casing, a shaft rotatably supported in said casing, a structure mounted in said casin about and in spaced relation to said shaft, said structure and said shaft having opposed surfaces and forming substantially sections of spheres having a common center at the axis of said shaft, a plurality of pairs of pintles between said opposed surfaces, each pintle having its ends mounted respectively in said structure and said shaft and connecting the same for rotation in unison, axially spaced bevel gears supported about the axis of said shaft between the latter and said structure, one of said gears being rotatable about said axis and the other of said gears being held against rotation, one of said gears having more teeth than the other gear, a shaft connected with said rotatable gear, plurality of pairs of planetary gears rotatably supported by the respective pintles, said pairs of gears being spaced about the first mentioned shaft, and the gears of each pair meshing one with the other and with the respective first mentioned gears, means in the space between said shaft and said structure forming channels about separated peripheral portions of each of said planetary gears, and means for delivering fluid to and discharging the same from each of said channels.

6. In a fluid displacement device of the gear type, a casing having a work chamber within the same, a shaft rotatably supported in said casing, two gears mounted in said work chamber concentric with the axis of said shaft, one of said gears being rotatable and the other of said gears being held against rotation, a second shaft connected with said rotatable gear, intermeshing planetary gears connected with the first mentioned shaft for rotation therewith and having geared connection with the first mentioned gears, inlet and outlet passages leading to and from said work chamber, a balancing chamber between said rotatable gear and a fixed part of said work chamber, and means for connecting said balancing chamber with said inlet passage to provide fluid pressure thereon to counteract the end thrust on said rotatable gear.

'7. In a fluid displacement device of the gear type, a, casing having a work chamber within the same, a shaft rotatably supported in said casing, two gears mounted in said work chamber concentric with the axis of said shaft, one of said gears being rotatable and the other of said gears being held against rotation, a second shaft connected with said rotatable gear, intermeshing planetary gears connected with the first mentioned shaft for rotation therewith and having geared connection with the first mentioned gears, two fluid passages connected with said work chamber either of which may be the inlet passage, a balancing chamber between said rotatable gear and a fixed part of said work chamber, ports leading from the respective passages to said chamber, and check valves in the respective ports to connect the inlet passage with said work chamber and to disconnect the other passage therefrom, whereby fluid under pressure will be admitted to said chamber to counterbalance end thrust on said rotatable gear.

CECIL A. MANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,287,118 Shore Dec. 10, 1918 1,636,259 Sweeney July 19, 1927 1,937,367 Vickers Nov. 28, 1933 2,240,874 Thomas et a1. May 6, 1941 2,311,237 Loveday Feb. 16, 1943 2,318,386 Haines May 4, 1943 2,333,885 Poulter Nov. 9, 1943 FOREIGN PATENTS Number Country Date 155,343 Germany Nov. 28, 1904 592,033 Germany Jan. 31, 1934, 669,695 Germany Jan. 2, 1939 

